9514 1404 393
Answer:
 47°
Explanation:
The law of sines helps you find angle T. From there, you can find angle S.
 sin(T)/t = sin(R)/r
 sin(T) = (t/r)sin(R) = (10/20)sin(104°)
 T = arcsin(sin(104°)/2) ≈ 29°
Then angle S is ...
 S = 180° -R -T = 180° -104° -29°
 ∠S = 47°